There has since been no sighting of the Boeing 777 except for debris spotted on satellite images in remote waters west of Australia.

Malaysian Prime Minister Najib Razak said last night that new analysis by the UK Air Accidents Investigation branch and tracking firm Inmarsat showed the plane’s location was “far from any possible landing sites”.

In a late news conference in Kuala Lumpur, he went on: “It is therefore with deep sadness and regret that I must inform you that, according to this new data, Flight MH370 ended in the southern Indian Ocean.”

He confirmed the families of the victims had been informed and added: “For them, the past few weeks have been heart-breaking. I know this news must be harder still.”

Relatives, who had been praying for a miracle for 17 days, were left screaming and crying uncontrollably after the news broke.

Some needed to be held up by their loved ones to stop them collapsing as the stress proved too much.

In Beijing about 50 relatives were given the news at the Lido hotel close to the airport.

Afterwards, they filed out of a conference room, stricken with grief. One woman collapsed to her knees and cried: “My son, my son!”

Another relative screamed: “It’s not possible!”

Medical teams arrived with several stretchers and at least one elderly man was carried out of the conference room. Minutes later a woman was taken out on another stretcher, her face ashen.

Nan Jinyan, whose brother-in-law Yan Ling was on the flight, said she was prepared for the worst when she heard the Prime Minister had announced a news conference.

Ms Nan said: “This is a blow to us, and it is beyond description.” Some also attacked Malaysia Airlines for delivering the news by text message.

One relative yelled: “We’ve been waiting for 17 days. You simply tell us this! Where is the proof? It’s wrong to announce the information like this!”

Rex

Search: Suspected objects in the southern Indian Ocean viewed from a Chinese IL-76 plane

However, a spokesman for Malaysia Airlines defended its actions and insisted it had spoken to some families face to face at the hotels where the company had put them up.

The spokesman said: “SMS and phone calls were made to those who are not in the hotels via our family support centre.”

Relatives of the Chinese victims also last night branded the Malaysian government “despicable” and the ­military ­“executioners”.

In a statement, they said: “Malaysia Airlines, the government of Malaysia, and the military forces of Malaysia have concealed, delayed and hidden the truth from the relatives and the people of the world.

“This despicable act aimed to fool the relatives of the 154 Chinese ­passengers has devastated us ­physically and mentally, while misleading and delaying the rescue operation, wasting a lot of manpower, material resources and leading to the loss of precious rescue time.

“If the 154 of our loved ones have lost their lives, then Malaysia Airlines, the government of Malaysia and the military are really the executioners.”

Meanwhile the daughter of Malaysian Andrew Nari, a Liverpool fan and chief steward on board the flight, spoke of her grief last night.

Maira Nari tweeted: “God loves you more daddy ... God loves them more.” She added: “I don’t know what to say, what to think. I feel so lost, so blank. I’m just so tired. ­Goodnight, daddy. Sigh .. *hugs*.”

It is feared the jet may never be salvaged as the area where it crashed is 23,000ft at it deepest point. Malaysian PM Mr Razak said London-based Inmarsat had employed “a type of analysis never before used in an ­investigation of this sort” to establish its location.

The new data revealed MH370 flew along the southern corridor, which investigators earlier said it may have travelled through based on “ping” signals sent by the plane after its communications were shut down. It concluded the airliner’s last ­position was “in the middle of the Indian Ocean, west of Perth”.

An aviation source also said last night that the jet would have hit the water at around 600mph after gliding from 35,000ft.

The source said: “The plane would not have dropped like a stone, it would have glided down for around 10-12 minutes after it exhausted its fuel.

Reuters

Announcement: Malaysia's Prime Minister Najib Razak

“It would have hit the water with a massive impact - as though the plane had landed on concrete.

“Nobody could have survived that. There would have been a huge explosion with the wings ripped off”.

The plane’s disappearance has baffled investigators. They are yet to rule out mechanical or electrical failure, hijacking, ­sabotage, terrorism or issues related to the mental health of the pilots.

Floating objects have also been spotted by Australian and Chinese planes in the southern Indian Ocean and ships were yesterday heading towards their location.

It was close to the area where unidentified objects were spotted by several satellites.

One boat was carrying equipment to detect the plane’s vital black box.

Malaysia Airlines said in a ­statement: “The multinational search operation will continue, as we seek answers to the ­questions which remain.”